diff --git a/runtime/optwin.vim b/runtime/optwin.vim
index 47e165f455..26c80e5ce0 100644
--- a/runtime/optwin.vim
+++ b/runtime/optwin.vim
@@ -1,11 +1,11 @@
 " These commands create the option window.
 "
 " Maintainer:	The Vim Project <https://github.com/vim/vim>
-" Last Change:	2025 Jul 25
+" Last Change:	2025 Aug 07
 " Former Maintainer:	Bram Moolenaar <Bram@vim.org>
 
 " If there already is an option window, jump to that one.
-let buf = bufnr('option-window')
+let buf = bufexists('option-window') ? bufnr('option-window') : -1
 if buf >= 0
   let winids = win_findbuf(buf)
   if len(winids) > 0